xref: /freebsd/lib/libc/rpc/auth_unix.c (revision 7750ad47a9a7dbc83f87158464170c8640723293)
1 /*	$NetBSD: auth_unix.c,v 1.18 2000/07/06 03:03:30 christos Exp $	*/
2 
3 /*
4  * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
5  * unrestricted use provided that this legend is included on all tape
6  * media and as a part of the software program in whole or part.  Users
7  * may copy or modify Sun RPC without charge, but are not authorized
8  * to license or distribute it to anyone else except as part of a product or
9  * program developed by the user.
10  *
11  * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
12  * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
13  * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
14  *
15  * Sun RPC is provided with no support and without any obligation on the
16  * part of Sun Microsystems, Inc. to assist in its use, correction,
17  * modification or enhancement.
18  *
19  * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
20  * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
21  * OR ANY PART THEREOF.
22  *
23  * In no event will Sun Microsystems, Inc. be liable for any lost revenue
24  * or profits or other special, indirect and consequential damages, even if
25  * Sun has been advised of the possibility of such damages.
26  *
27  * Sun Microsystems, Inc.
28  * 2550 Garcia Avenue
29  * Mountain View, California  94043
30  */
31 
32 #if defined(LIBC_SCCS) && !defined(lint)
33 static char *sccsid2 = "@(#)auth_unix.c 1.19 87/08/11 Copyr 1984 Sun Micro";
34 static char *sccsid = "@(#)auth_unix.c	2.2 88/08/01 4.0 RPCSRC";
35 #endif
36 #include <sys/cdefs.h>
37 __FBSDID("$FreeBSD$");
38 
39 /*
40  * auth_unix.c, Implements UNIX style authentication parameters.
41  *
42  * Copyright (C) 1984, Sun Microsystems, Inc.
43  *
44  * The system is very weak.  The client uses no encryption for it's
45  * credentials and only sends null verifiers.  The server sends backs
46  * null verifiers or optionally a verifier that suggests a new short hand
47  * for the credentials.
48  *
49  */
50 
51 #include "namespace.h"
52 #include "reentrant.h"
53 #include <sys/param.h>
54 
55 #include <assert.h>
56 #include <err.h>
57 #include <stdio.h>
58 #include <stdlib.h>
59 #include <unistd.h>
60 #include <string.h>
61 
62 #include <rpc/types.h>
63 #include <rpc/xdr.h>
64 #include <rpc/auth.h>
65 #include <rpc/auth_unix.h>
66 #include "un-namespace.h"
67 #include "mt_misc.h"
68 
69 /* auth_unix.c */
70 static void authunix_nextverf (AUTH *);
71 static bool_t authunix_marshal (AUTH *, XDR *);
72 static bool_t authunix_validate (AUTH *, struct opaque_auth *);
73 static bool_t authunix_refresh (AUTH *, void *);
74 static void authunix_destroy (AUTH *);
75 static void marshal_new_auth (AUTH *);
76 static struct auth_ops *authunix_ops (void);
77 
78 /*
79  * This struct is pointed to by the ah_private field of an auth_handle.
80  */
81 struct audata {
82 	struct opaque_auth	au_origcred;	/* original credentials */
83 	struct opaque_auth	au_shcred;	/* short hand cred */
84 	u_long			au_shfaults;	/* short hand cache faults */
85 	char			au_marshed[MAX_AUTH_BYTES];
86 	u_int			au_mpos;	/* xdr pos at end of marshed */
87 };
88 #define	AUTH_PRIVATE(auth)	((struct audata *)auth->ah_private)
89 
90 /*
91  * Create a unix style authenticator.
92  * Returns an auth handle with the given stuff in it.
93  */
94 AUTH *
95 authunix_create(machname, uid, gid, len, aup_gids)
96 	char *machname;
97 	int uid;
98 	int gid;
99 	int len;
100 	int *aup_gids;
101 {
102 	struct authunix_parms aup;
103 	char mymem[MAX_AUTH_BYTES];
104 	struct timeval now;
105 	XDR xdrs;
106 	AUTH *auth;
107 	struct audata *au;
108 
109 	/*
110 	 * Allocate and set up auth handle
111 	 */
112 	au = NULL;
113 	auth = mem_alloc(sizeof(*auth));
114 #ifndef _KERNEL
115 	if (auth == NULL) {
116 		warnx("authunix_create: out of memory");
117 		goto cleanup_authunix_create;
118 	}
119 #endif
120 	au = mem_alloc(sizeof(*au));
121 #ifndef _KERNEL
122 	if (au == NULL) {
123 		warnx("authunix_create: out of memory");
124 		goto cleanup_authunix_create;
125 	}
126 #endif
127 	auth->ah_ops = authunix_ops();
128 	auth->ah_private = (caddr_t)au;
129 	auth->ah_verf = au->au_shcred = _null_auth;
130 	au->au_shfaults = 0;
131 	au->au_origcred.oa_base = NULL;
132 
133 	/*
134 	 * fill in param struct from the given params
135 	 */
136 	(void)gettimeofday(&now, NULL);
137 	aup.aup_time = now.tv_sec;
138 	aup.aup_machname = machname;
139 	aup.aup_uid = uid;
140 	aup.aup_gid = gid;
141 	aup.aup_len = (u_int)len;
142 	aup.aup_gids = aup_gids;
143 
144 	/*
145 	 * Serialize the parameters into origcred
146 	 */
147 	xdrmem_create(&xdrs, mymem, MAX_AUTH_BYTES, XDR_ENCODE);
148 	if (! xdr_authunix_parms(&xdrs, &aup))
149 		abort();
150 	au->au_origcred.oa_length = len = XDR_GETPOS(&xdrs);
151 	au->au_origcred.oa_flavor = AUTH_UNIX;
152 #ifdef _KERNEL
153 	au->au_origcred.oa_base = mem_alloc((u_int) len);
154 #else
155 	if ((au->au_origcred.oa_base = mem_alloc((u_int) len)) == NULL) {
156 		warnx("authunix_create: out of memory");
157 		goto cleanup_authunix_create;
158 	}
159 #endif
160 	memmove(au->au_origcred.oa_base, mymem, (size_t)len);
161 
162 	/*
163 	 * set auth handle to reflect new cred.
164 	 */
165 	auth->ah_cred = au->au_origcred;
166 	marshal_new_auth(auth);
167 	return (auth);
168 #ifndef _KERNEL
169  cleanup_authunix_create:
170 	if (auth)
171 		mem_free(auth, sizeof(*auth));
172 	if (au) {
173 		if (au->au_origcred.oa_base)
174 			mem_free(au->au_origcred.oa_base, (u_int)len);
175 		mem_free(au, sizeof(*au));
176 	}
177 	return (NULL);
178 #endif
179 }
180 
181 /*
182  * Returns an auth handle with parameters determined by doing lots of
183  * syscalls.
184  */
185 AUTH *
186 authunix_create_default()
187 {
188 	AUTH *auth;
189 	int ngids;
190 	long ngids_max;
191 	char machname[MAXHOSTNAMELEN + 1];
192 	uid_t uid;
193 	gid_t gid;
194 	gid_t *gids;
195 
196 	ngids_max = sysconf(_SC_NGROUPS_MAX) + 1;
197 	gids = malloc(sizeof(gid_t) * ngids_max);
198 	if (gids == NULL)
199 		return (NULL);
200 
201 	if (gethostname(machname, sizeof machname) == -1)
202 		abort();
203 	machname[sizeof(machname) - 1] = 0;
204 	uid = geteuid();
205 	gid = getegid();
206 	if ((ngids = getgroups(ngids_max, gids)) < 0)
207 		abort();
208 	if (ngids > NGRPS)
209 		ngids = NGRPS;
210 	/* XXX: interface problem; those should all have been unsigned */
211 	auth = authunix_create(machname, (int)uid, (int)gid, ngids,
212 	    (int *)gids);
213 	free(gids);
214 	return (auth);
215 }
216 
217 /*
218  * authunix operations
219  */
220 
221 /* ARGSUSED */
222 static void
223 authunix_nextverf(auth)
224 	AUTH *auth;
225 {
226 	/* no action necessary */
227 }
228 
229 static bool_t
230 authunix_marshal(auth, xdrs)
231 	AUTH *auth;
232 	XDR *xdrs;
233 {
234 	struct audata *au;
235 
236 	assert(auth != NULL);
237 	assert(xdrs != NULL);
238 
239 	au = AUTH_PRIVATE(auth);
240 	return (XDR_PUTBYTES(xdrs, au->au_marshed, au->au_mpos));
241 }
242 
243 static bool_t
244 authunix_validate(auth, verf)
245 	AUTH *auth;
246 	struct opaque_auth *verf;
247 {
248 	struct audata *au;
249 	XDR xdrs;
250 
251 	assert(auth != NULL);
252 	assert(verf != NULL);
253 
254 	if (verf->oa_flavor == AUTH_SHORT) {
255 		au = AUTH_PRIVATE(auth);
256 		xdrmem_create(&xdrs, verf->oa_base, verf->oa_length,
257 		    XDR_DECODE);
258 
259 		if (au->au_shcred.oa_base != NULL) {
260 			mem_free(au->au_shcred.oa_base,
261 			    au->au_shcred.oa_length);
262 			au->au_shcred.oa_base = NULL;
263 		}
264 		if (xdr_opaque_auth(&xdrs, &au->au_shcred)) {
265 			auth->ah_cred = au->au_shcred;
266 		} else {
267 			xdrs.x_op = XDR_FREE;
268 			(void)xdr_opaque_auth(&xdrs, &au->au_shcred);
269 			au->au_shcred.oa_base = NULL;
270 			auth->ah_cred = au->au_origcred;
271 		}
272 		marshal_new_auth(auth);
273 	}
274 	return (TRUE);
275 }
276 
277 static bool_t
278 authunix_refresh(AUTH *auth, void *dummy)
279 {
280 	struct audata *au = AUTH_PRIVATE(auth);
281 	struct authunix_parms aup;
282 	struct timeval now;
283 	XDR xdrs;
284 	int stat;
285 
286 	assert(auth != NULL);
287 
288 	if (auth->ah_cred.oa_base == au->au_origcred.oa_base) {
289 		/* there is no hope.  Punt */
290 		return (FALSE);
291 	}
292 	au->au_shfaults ++;
293 
294 	/* first deserialize the creds back into a struct authunix_parms */
295 	aup.aup_machname = NULL;
296 	aup.aup_gids = NULL;
297 	xdrmem_create(&xdrs, au->au_origcred.oa_base,
298 	    au->au_origcred.oa_length, XDR_DECODE);
299 	stat = xdr_authunix_parms(&xdrs, &aup);
300 	if (! stat)
301 		goto done;
302 
303 	/* update the time and serialize in place */
304 	(void)gettimeofday(&now, NULL);
305 	aup.aup_time = now.tv_sec;
306 	xdrs.x_op = XDR_ENCODE;
307 	XDR_SETPOS(&xdrs, 0);
308 	stat = xdr_authunix_parms(&xdrs, &aup);
309 	if (! stat)
310 		goto done;
311 	auth->ah_cred = au->au_origcred;
312 	marshal_new_auth(auth);
313 done:
314 	/* free the struct authunix_parms created by deserializing */
315 	xdrs.x_op = XDR_FREE;
316 	(void)xdr_authunix_parms(&xdrs, &aup);
317 	XDR_DESTROY(&xdrs);
318 	return (stat);
319 }
320 
321 static void
322 authunix_destroy(auth)
323 	AUTH *auth;
324 {
325 	struct audata *au;
326 
327 	assert(auth != NULL);
328 
329 	au = AUTH_PRIVATE(auth);
330 	mem_free(au->au_origcred.oa_base, au->au_origcred.oa_length);
331 
332 	if (au->au_shcred.oa_base != NULL)
333 		mem_free(au->au_shcred.oa_base, au->au_shcred.oa_length);
334 
335 	mem_free(auth->ah_private, sizeof(struct audata));
336 
337 	if (auth->ah_verf.oa_base != NULL)
338 		mem_free(auth->ah_verf.oa_base, auth->ah_verf.oa_length);
339 
340 	mem_free(auth, sizeof(*auth));
341 }
342 
343 /*
344  * Marshals (pre-serializes) an auth struct.
345  * sets private data, au_marshed and au_mpos
346  */
347 static void
348 marshal_new_auth(auth)
349 	AUTH *auth;
350 {
351 	XDR	xdr_stream;
352 	XDR	*xdrs = &xdr_stream;
353 	struct audata *au;
354 
355 	assert(auth != NULL);
356 
357 	au = AUTH_PRIVATE(auth);
358 	xdrmem_create(xdrs, au->au_marshed, MAX_AUTH_BYTES, XDR_ENCODE);
359 	if ((! xdr_opaque_auth(xdrs, &(auth->ah_cred))) ||
360 	    (! xdr_opaque_auth(xdrs, &(auth->ah_verf))))
361 		warnx("auth_none.c - Fatal marshalling problem");
362 	else
363 		au->au_mpos = XDR_GETPOS(xdrs);
364 	XDR_DESTROY(xdrs);
365 }
366 
367 static struct auth_ops *
368 authunix_ops()
369 {
370 	static struct auth_ops ops;
371 
372 	/* VARIABLES PROTECTED BY ops_lock: ops */
373 
374 	mutex_lock(&ops_lock);
375 	if (ops.ah_nextverf == NULL) {
376 		ops.ah_nextverf = authunix_nextverf;
377 		ops.ah_marshal = authunix_marshal;
378 		ops.ah_validate = authunix_validate;
379 		ops.ah_refresh = authunix_refresh;
380 		ops.ah_destroy = authunix_destroy;
381 	}
382 	mutex_unlock(&ops_lock);
383 	return (&ops);
384 }
385